Add zlogin to build zcompdump.zwc.

dotfiles/zlogin

@@ -0,0 +1,8 @@
+# Execute code that does not affect the current session in the background.
+{
+  # Compile the completion dump to increase startup speed.
+  zcompdump="${ZDOTDIR:-$HOME}/.zcompdump"
+  if [[ -s "$zcompdump" && (! -s "${zcompdump}.zwc" || "$zcompdump" -nt "${zcompdump}.zwc") ]]; then
+    zcompile "$zcompdump"
+  fi
+} &!